OK so assuming it was not just a case of him taking some space for you both to cool off?
You're saying this is the first time he has done this? ...yet the way you've worded things in oarts of your post also implies this is not the case...so I'm a bit confused.
Op the issue is either incompatibility in communication (you like to resolve things ASAP where as he just likes to take a breather and assume things are resolved when he comes back). In which case, this provably won't work long term. I mean you can talk with him and make it clear that you like to resolve things same day if there are ever disagreements. But it might be that he just doesn't have any conflict resolutions skills and will never be able to do so. Besides, it really isn't somethi g you should have to say to him because a normal, empathetic person would recognise that disappearing for a few days could be seen as passive aggressive.
Alternatively therefore, it could be that he is manipulative. Most people know fine that if you walk away on an argument, things can fester.
What did YOU learn in your childhood that has you tying yourself in knots looking for a way to excuse behaviour that manipulative or not, does not work work for you?
Is the one on a forum looking into how to make life easier for you both? Is he buggary.
You have to be very careful op. At best, he doesn't share your communication style. Which really, is a game ender on its own tbh. And certainly should be if this is a newish relationship. At worst, he is manipulative and vanishes in order to punish you for daring to disagree with him.
If behaviour is unacceptable to you then you don't have to look for reasons to excuse it. Your responsibility is to look out for yourself. If you insist on giving things a go then set boundaries for YOURSELF. And if people cross them, walk away.
Often people are quick to blame the man's childhood on here for bs. He is a grown man. His childhood is irrelevant. Totally. Unless it has emotionally stunted him and he is incapable of introspection...aka a sociopath or a narcissist. In which case, you run for the bloody hills!